


The War

by Mama_Comic



Category: Undertale (Video Game)
Genre: Battle, Death, Elemental - Freeform, Fighting, Gaster - Freeform, Humans, Shippy undertones, Violence, War, gaster x OC - Freeform, sailed ship
Language: English
Status: Completed
Published: 2019-04-25
Updated: 2019-04-25
Packaged: 2020-01-31 18:21:12
Rating: Not Rated
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 2,357
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18596860
Author URL: https://archiveofourown.org/users/Mama_Comic/pseuds/Mama_Comic
Summary: Gaster has never been in a war before. When he’s forced to kill to save a fellow monster, he learns maybe the elemental is a little more like him then he initially assumed.





	The War

**Author's Note:**

> So this is my first time posting a Fic I’ve written.. this isn’t nessicarily shippy, really. It’s based off an RP, and is set in the past.

What was war, really? A clashing of iron and steel, emotions on both sides burning like hellfire, both driven by an inane sense of justice. The battle field was nothing like Gaster had ever seen before. Then again, he’d never been to war before. Skeletons weren’t built for war. They were notorious for being liabilities, weak both in magic and physicality. But gaster was a unique exception... he was physically weak, like any other of his kind. However his magical prowess was something he took great pride in. He’d mastered the lost the form of summoning, and with these giant constructs he unleashed heavy, blinding blasts of magic that annihilated all that stood in their path.  
He’d never fought before, though, despite all his ability. He felt so very small standing in the wide open field surrounded by monsters and humans alike. The open air felt suffocating for the first time in his life, weighted by the stench blood and dust. And for the first time since his early days of training, he was petrified. The only thing stopping him from turning to run was the fact that he’d never be able to forgive himself for abandoning his kind. Unlike most of the other soldiers, gaster had no real reason to fight. No family to protect or avenge, no significant sense of pride in his race. He was actually of the opinion that humans aren't entirely in the wrong, though he would be tried for treason if he ever voiced such an opinion.  
Gaster was startled out of his thoughts by a blast of fire somewhere amongst the monsters, had an elemental fallen? Or worse, a boss monster?   
Stars guide me.  
It was all he could think. It was all any of them could think. Surely if they were the victims in this war, the gods would have mercy. The wave of humans had to stop eventually. They had to win. Right?  
The armored skeleton weaved his way through the bodies- both standing and slain- and to the origin point of the blast, only to find a strange looking blue elemental grappling with a human.. and the human seemed to be winning. The human wore simple chainmail and swing her sword with a fierce swiftness that anyone would have difficulty matching. The fight between them looked more like a dance, both moving with a deadly precision and grace. Only this was a dance that would end in death.  
Gaster soul squeezed in his chest; he’d never taken a life himself, not yet. He had been mostly ignored- the humans hardly saw a puny, short skeleton as a threat. Watching the elemental fight so fiercely.. the way he moved, the expression on his face.. the elemental had a great pain in his soul. It was impossible not to see. What pained him and why.. Well, only the warrior knew.  
Gaster shook his head, internally berating himself. He couldn’t afford to get so distracted! He almost turned away from the fight, but noticed the angry look becoming a panicked one as the human began to drive the elemental back. And that’s when gaster realized the elemental was losing. When the monsters eyes met Gasters, his soul gave a strange lurch and gaster felt as if his body moved without his permission.  
He drew his sword and took exactly six steps forward, before driving the sharp blade into the humans neck from behind, able to feel as it sank through muscle and sinew like a hot knife through butter. There was a horrible, sick gurgling as the human dropped her weapon and grabbed at the blade protruding through her throat, blood welling up in the gashes in her hands as gaster yanked the blade back out, and a spray of blood spattered both him and the elemental as the human staggered then fell, bleeding profusely. She twitched once, twice, then became still as the cold embrace of death took her.  
Gaster simply stared down at the body, feeling sick to his stomach as his LV ticked up to two. He was a killer now. A soldier, right and proper. He’d taken a life. He’d killed a human. The elemental snapped out of his own reverie as gasters blade fell from his hands, smeared in gore.   
“Are.. you alright?”  
Gaster didn’t answer. He couldn’t take his eyes off the cooling corpse, his very own handiwork. The horrible nausea built, and he felt it in the back of his throat before he bent over and was sick, a runny mix of magic and half digested food. The elemental winced.  
“That’s.. probably a no then.”  
He gingerly stepped over the body and gently laid a hand on the quivering skeletons shoulder. “Come on, lets.. get somewhere safer.”  
It didn’t take a genius to recognize that this monster wasn’t really suited for war. Gaster gave a small, weak nod. He had to get out of there, away from the cloying stench of blood. He felt like a stranger in his own body;   
I am a murderer.  
“I’m.. Von, by the way.”  
Gaster gave no indication he had heard, as the elemental urged him forward. Gasters face flushed purple as he stepped in the still warm pool of blood that was beginning to sink into the dirt. He felt..Unclean. He took slow, staggering steps and more than once he nearly fell, always caught by warm, strong hands.   
It didn’t take long for them to reach the back of the encampment that was under siege, though it took a short while to find a place where the elementals natural glow wouldn’t give them away. They sat opposite each other in the dirt under a tree, the sounds of dying in the distance as the battle continued to rage.  
“...that was your first, wasn’t it?”  
Gaster twitched slightly. His first. It implied there would be another. And another after that.  
Murderer.  
“...i..”  
Von startled slightly at Gasters attempt at speech- until now, he’d been completely silent.   
“...I have.. never been on a battlefield before. I’m… i am a Doctor. Or.. I.. I was..”  
A doctor.. he had been, once. Had saved the lives of both human and monsters alike. Had fought against disease and injury to bring others through to the other side. He felt disgusting. He’d taken an oath never to do harm.   
Murderer.  
“I.. kinda figured you were new to this mess. But.. thank you.”  
Gaster felt repulsed as he looked at Von, expressing twisting into something dark.  
“Thank you? For what? Taking the life of someone I had never met?! I had no right- I-I am- I swore to save lives! I promised-“  
“You did save a life.”  
Von quietly interjected. Gaster choked on bile as his mind forcibly brought fourth images of the body, the blood..  
“She’s dead.”  
“And I’m alive.”  
That’s.. that’s right. This.. this monster had been fighting the human. He would have been killed had gaster not.. as Gaster took this in, Von gave the skeleton a small, sad smile.  
“It’s not your fault. Nobody is at fault but the humans.”  
Gaster slowly lifted his gaze to meet Vons once more.  
“Does it get easier?”  
“What do you mean?”  
“Killing. Does.. it ever get easier?”  
Von looked down. Easier…  
“No. It never gets any easier.You’ll always ask yourself if it was worth it. If they really had to die. But it doesn’t matter in the moment it happens, because at the end of the day it was them or you. They’re fighting for their life, as you fight for your own. Only the gods can decide who’s is valued more.”  
Gaster nodded numbly, wrapping his arms around himself only to yank his hands back as if he’d been burned. His armor was slick with cold, half congealed blood, sticky and wet. He looked ready to get sick again.  
“..let’s get this off of you.”  
Gasters mind went back to analyzing the elemental as he was helped out of his soiled armor. If he thought about what had just happened he’d only panic again, only get angry again.   
The elemental had been a father at some point. He had to have been. He was patient, the kind of patience gaster had only ever seen in parents. And he fought with such ferocity, yet abandon.. this was a man with nothing left to lose. He was a father.... But he was no longer. Did that mean he had a mate? A quick glance at Vons hands as he threw Gasters unwanted armor into the corner answered the question fairly easily. A simple gold band was sported on his finger. Married then. And.. likely to a human. Monsters didn’t typically exchange rings.  
Gaster gave a breathless little laugh, which caught the elementals attention again.  
“What’s so funny?”  
“Your like me.”  
Von had to pause at that. Like him? In what manner? He was neither new to war nor skeletal, and this monster knew nothing else of him.   
“What do you mean?”  
“You once loved humans.”  
Von went quiet, his soul giving a strange, numb throb. That was.. certainly one way to put it. But how had gaster known?  
“How did you-“  
“Your ring. Monsters don’t.. exchange rings. The flame around it is discolored. You’ve never taken it off.”  
Von looked down at his hand, giving a sound that was something between a hum and a nervous laugh. This monster had known him for all of ten minutes and already had figured this much about him.. it was startling. Scary, even. Gaster and Von sat in silence for a long moment before Gaster looked down.  
“I..I’m sorry. I shouldn’t say such things, it’s not my place. It’s just… I wasn’t a purely monster doctor, is all. I’ve saved both the lives of humans, and the lives of monsters. Children, adults, elderly.. I know there’s more to humans then war and bloodthirst. But nobody listens to me. I would be tried for treason if anyone found out.”  
Von gave a bitter laugh. Treason. That’s right. If his own king had found out he’d dared to love a human, regardless of the circumstance, regardless of her slaughter, he would likely be put to death. Perhaps they were alike after all.  
Gaster let out a shaking breath, and Von returned to looking at the skeleton. He was.. gaster looked old. Not in body, in fact Von estimated gaster was barely a hundred years old. No.. he looked old in soul. In the way he carried himself and the haunted look in his eyes.   
They sat in relative silence for an unknown amount of time, until without warning, the tree they hid beneath shook violently with some sort of blast, and both of them scrambled out.   
“More monsters! Here!”  
Gasters soul felt cold and weak as he realized they had been surrounded by humans. Which could only mean..  
They had lost.  
Von positioned gaster behind him, face twisted into an ugly snarl as heat built up around them. But he froze in place when he saw the horrified look on each humans face, and the. Heard the steady, high pitched whine behind him. When Von turned, he saw Gaster with his arm up, eyes full of tears as an absolutely massive canine skull floated above him, jaw hanging slightly open and molten magic dripping sluggishly from its maw, the consistency of syrup.   
He barely had time to dive away as gaster brought his arm down in a swift motion and the beastly skulls jaw dropped open entirely and a deafening roar filled the air. The light was blinding, the heat intense even for Von, but it only lasted a few seconds before the light faded. Gaster was panting so hard he almost gagged himself, magic drained nearly to nothing. Vons head whipped over to where the attack had hit. Not a single human remained.. they hadn’t even had time to scream, burned alive nearly instantly into blackened husks on the ground. Gaster was frozen in place, save for his labored breathing.  
Von stood slowly. The blaster was still hovering above gasters head, the area gone silent.  
“..hey.. Buddy.. “   
The skeletons eyes snapped to Von, and the magic began to built again, the skeletons eyes unseeing and terrified. Slowly, delicately, the four-armed monster wrapped his arms around gaster, and the whining went silent as the blaster almost immediately dissipated.  
“...I..I….i..!”  
Von shook his head slowly.  
“Don’t, just.. come on. I know the place we’re supposed to regroup if things went..”   
his gaze drifted to the burnt bodies.  
“...badly. It’s a one way cave system.”  
Gaster nodded numbly, and allowed himself to be lead in yet another direction.

. . .

The humans sealed them underground after a final battle, wherein so many lives were lost that their numbers dwindled to an estimated two hundred. The final battle had been bloody, and there was no telling how many had taken their own life rather then submit to confinement.   
Gaster watched in helpless silence as the barrier was erected, seven mages giving their very lives to oppress a race that had only wanted to be free. It made him feel sick to know the race he’d once helped to treat and save had betrayed them so completely and thoroughly.  
In the end, he’d had to take far more lives. Enough so that he hardly blinked at it any more. The innocent, naive doctor he once was.. that doctor was dead, he could never be that way again. Not with this stain on his soul. He was different now.

He never saw Von again. Despite looking for him for years, asking everyone he could about the unique elemental. Many soldiers reported seeing him in the Final Battle, but none had seen him since the barrier went up. Gaster could only speculate what had happened. Had he joined the countless others to take their own lives, preferring to die under the stars? Had he jumped from the falls of the underground? Was he in hiding?..... had he stayed behind?  
In the coming centuries, everything that followed.. the too-brief encounter was ultimately forgotten. And he no longer wondered what could have been.


End file.
